The automotive industry has been turning to lighter weight, high strength materials. Body panels or components made of such materials tend to be thinner than those they are replacing. As a result, it is sometimes necessary to include a reinforcing rail to such components to enable appropriate management of noise, vibration and harshness (NVH).
SMC is one class of lightweight materials that has been used in the automotive industry. For example, removable hard top roofs have been assembled from SMC components adhesively bonded together. Adhesive bonding is used because SMC is not suitable for other similar joining operations, such as welding. Although convectively heating the components, such as occurs during baking of an e-coat, could provide some curing of the adhesive bond, this heating does not occur at an appropriate point in the manufacturing process, and would almost certainly require additional bake time to insure the necessary curing of the adhesive bond. Thus, it is generally acknowledged that heat must be conductively applied directly to both sides of the panels being joined at the adhesive bond in order to cure the adhesive sufficiently and quickly enough for the automotive manufacturing industry.
As a result, SMC is considered unsuitable in the automotive industry in situations where conduction heater access to either side of the panels being joined at the adhesive bond is prevented. Thus, skilled artisans in the automotive industry would either use a different material in an assembly, or avoid configurations requiring bonding of two components where such two sided heater access is prevented. For example, reinforcing members of prior removable automotive SMC hard top roofs are designed to accomplish their purposes, including appropriately managing component NVH, without being additionally bonded to adjacent side or rear walls of the hardtop.